DieselShip's Online Content Library

Q1. List the factors that cause deterioration of the frequency response of a transistor amplifier. Explain how each factor affects the performance of the amplifier and the portion of the frequency range where it is effective. (16)

Q3. With reference to the provision of a shore electrical supply to a ship:

a) Sketch an arrangement for taking A.C. Shore supply and checks to be carried out prior taking shore connection? (8)

b) Describe the methods of safely connecting the arrangement sketched in (A) to the shore supply? (8)

Q4. A) Explain the significance of the root-mean-square value of an alternating current or voltage waveform. Define the form factor of such a waveform. (6)

b) A total load of 8000 kW at 0.8 power factor is supplied by two alternators in parallel. One alternator supplies 6000 kW at 0.9 power factor. Find the KVA rating of the other alternator and the power factor. (10)

Q5. (a)  Sketch an arrangement showing the principal of a proportional plus Integral (P  + I) control loop. (6)

(b) Compare the series and parallel resonance circuits. Find the frequency at which the following circuit resonates. (10)

Q6. a) Explain the potential hazards if liquid-cooled transformers are used. (6)
b) What are the losses in transformers? Mention the various factors which affect these losses. In a 25 KVA, 3300/233 V, single phase transformer, the iron and full-load Cu. Losses are respectively 350 and 400 Watts. Calculate the efficiency at half-full load 0.8 power factor. (10)

Q9. With reference to an automatic water sprinkler, fire detecting alarm and extinguishing system for accommodation spaces:

a) Sketch a typical system. (4)

b) Describe the operation of this system. (4)

c) State the sources of water available. (2)

d) Describe the sprinkler head and its operation. (3)

e) State how the temperature rating of the sprinkler head is determined. (3)